Slab and building construction



June 15, 1937. c. F. DAVIS 2,083,987

' SLAB AND BUILDING CONSTRUCTION Filed Feb. 7, 1933 I 8 Sheets-Sheet 1June 15, 1937. c. F. DAVIS SLAB AND BUILDING CONSTRUCTION r 8Sheets-Sheet 5 Filed Feb. 7, 1953 INVENTOR.

ATTORNEY.

June 15 1937. .c. F. DAVIS SLAB AND BUILDING con'smuq'rion Filed Feb.'7, 1953 8 Sheets-Sheet 4 f/4' INVENTOR.

June 15, 1937. 4 F, D VIS 2,083,987

SLAB AND BUILDING CONSTRUCTION INVENTOR. Qflf/ff ffiAIV/i,

Fyizz.

4 26 30 ATTORNEY.

Filed Feb. '7, 1935 8 Sheets-Sheet 5 I .6. F. DAVIS SLAB AND BUILDINGCONSTRUCTION June 15, 1937.

Filed Feb. '7, 1955 s Sheets-Sheet e llllllillllplv INVENTOR. C(A'fiff/Tflaw/a,

m o w A June 15, 1937. c. F. DAVIS SLAB AND BUILDING CONSTRUCTION FiledFeb. 7," 1953 v 8 Sheets-Sheet 7 I INVENTOR. QAfiKf/Tfi ATTORNEY.

June 15, 19370 c, F, DAWS 2,083,987

SLAB AND BUILDING C ONSTRUCT ION 6 V INVENTOR. CQAWA f/flJ/AF,

\ l w iggie 1 5 4 5653 '54 4 ATTORNEY.

Patented June 15, 1937 UNITED STATES PATENT OFFICE mesne assignments, toAmerican Cyanamid & Chemical Corporation, a corporation of DelawareApplication February '1, 1933, Serial No. 655,591

9 Claims.

The present invention relates to precast slabs having a body of setcementitious material, of which gypsum is typical, and carrying at theedges of such bodies metal elements which serve not only to protect theedges during shipment, erection or other handling, but which also lendstrength to building constructions involving the use of such slabs tothe end that load carrying ability is developed in such constructionsfar in 10 excess of anything which could be expected without such edgereinforcements.

The invention is not only concerned with such slabs per se but alsocontemplates a building construction involving such slabs together withthe 5 plates or iastening devices for securing the individual slabstogether, the mechanism for hanging such slabs from overhead supportsand other devices as will be more fully described hereinafter.

The principal object of the invention is the pro- 20 vision of a slabwhich may have universal application to building constructions whetherin a wall, floor, roof, partition, or the like.

One of the important objects of the invention is the provision of arectangular slab in which a channel runs longitudinally on one facethereof, that is, where the extreme edge portions of the 4 slab are ofgreater depth than points intermediate the edges.

It is another important object of the invention to provide a buildingconstruction involving the use of such slabs where the metallic elementson adjacent slabs so interlock and inter-engage that v such combinedmetallic elements will in effect form a sustaining beam when said slabsare used 35 together to form floors, roofs, walls, partitions or thelike, without in many cases the need for supplying other beams, girders,purlins, columns or the like.

It is another important object of the invention 40 to provide a slabwhich while of inherently weak material is so reenforced at the edgeportions with metallic structural members that greater supportingelement spacing maybe used over and above anything which has gone beforeand which 45 in some cases may even exceed the total length of theindividual slabs. V

A still other important object of the invention is the provision of abuilding construction whether a wall, floor or roof, in which theindividual slabs making up the composite structure are provided withchannels in one 'face thereof, and the utilization of these channels toreceive water, gas or heating pipes, electrical conduits or the like and55 in some cases utilizing such channels as conduits for airconditioning or heating or cooling fluids, or even floor fills. Anotherimportant object of the invention is the provision of slabs having metalmembers at or on their edge portions, so that they may be applied tobuilding constructions without definite heed being paid to the slablengths, that is, such slabs may be applied at random and cut into theproper length to fit the particular location to which they are applied.In the case of floors,- s'uch slabs may be laid without regard to beamspaces, either with or without additional reinforcements between slabs.v In the case of walls, they may be applied with entire disregard toeventual openings such as windows and doors, which can later be cut outin the proper location without in any way affecting the strength of thewall in which the opening occurs. In the case of roofs, it is proposedto lay such slabs in the direction of slope thereof in random lengths,and where a slab would normally project beyond the roof ridge or peak,the slab may be cut partially therethrough, without completely severingthe metal edge element, bent down over the other side of the peak andcontinued at random. Such a construction has the advantage of making adefinite tie over the ridge or peak without a break on each sidethereof, which greatly enhances the entire strength of the structure.

Other advantages and objects will appear as the description proceeds.

To this end the invention in one of its forms contemplates the provisionof a slab having a body of set cementitious material of which gypsum,

either with or without admixtures, is typical, the edge portions ofwhich are of greater thickness than the point intermediate such edges]It is preferred that these edges shouldhave embedded therein or carriedthereon, metal elements adapted to engage and co-operate with acomplementary metallic member on an adjacent slab edge. In the preferredform such co-operative interlocking parts may be of a tongued andgrooved type so that the two parts when meshed or interlockedtogethershall form a substantial I beam. While one approved form of interlockingjoint has been shown in the drawings, yet obviouslymany other forms willoccur to those skilled in.the art and the invention is, of course, to beconstrued to cover any interlock between adjacent slabs which will notdetract from the strength of the units or their load sustaining capacitybut which on the contrary will develop strengths therebetween far inexcess of that inherent in the slabs themselves.

The invention further contemplates that in the case of such slabs beingincorporated into walls whether inside or out, having openings thereinsuch as windows or doors, in many cases such 5 walls may be erected intoto and then the openings made therein wherever desired, by merelycutting through the slab body and the metal edge 'witha suitablesevering device. The severed slabs at the top of' such openings may beaddi- 10 tionally secured together as by soldering or weld- 20 beentirely supported from the metal elements of the adjacent wall slabs.

The invention further contemplates the use of face channels in suchslabs to carry gas, water or electrical conduits and heating or cooling25 fluids for conditioning heating or cooling the houses or roomsconstructed of such slabs, or

floor fills for insulation purposes or to support a floor finish of anydesired type.

In some instances it will be found desirable 30 to laterally reinforcesuch slabs as by ribs or metallic elements extending or sprung betweenthe metallic edge members, and the invention contemplates the use ofsuch lateral reinforcements whether such slabs are of gypsum or any 5other material, but for the sake of lightness gypsum is preferred. Suchribs or metallic reinforcements may occur in one or more'places in eachslab.

The invention further consists in the novel arrangement, combination andconstruction of parts more fully hereinafter described and shown in theaccompanying drawings, in which I Fig. 1 is a diagrammatic view of ahouse constructed according to this invention.

Fig. 2 is an elevation partly in section through -a wall and adjacentfloor and ceiling.

Fig. 3 is a view along the line 3--3 of Fig. 2.

Fig. 4 is a sectional plan view of two adjacent walls and including aplan view of a floor section.

Fig. 5 is a sectional view along the line 5--5 of Fig. 4 slightlymodified. I

Fig. 6 is a fragmentary perspectiveview of a wall showing the method ofsupporting a floor therefrom and showing a stripped floor slab toindicate its interior reinforcement.

Fig. 7 is a view of a combined wall and floor plate. Fig. 8 is-a viewshowing a combined wall and roof plate.

Fig. 9 is a perspective view of a wall showin a method of supporting aninterrupted or severed slab over a window or door opening.

Fig. 10 is a partial perspective detail of the supporting plate of Fig.9.

Fig. 11 is a sectional elevation showing the details of .joining a floorand supported and supporting walls. I

Fig. 12 is a sectional view through a reinforced floor.

Fig. 13 is a perspective detail of the reinforce of Fig. 12.

Fig. 14 is a plan view of a floor or root in which the span betweenbeams is greater than the 75 total length of the slabs.

I Fig. 15 is a perspective view of a slabextending with two planes asover a roof peak.

Fig. 16 is a plan view of a-modified slab.

Fig. 17 is a sectional view along the line |1-l1 of Fig. 16. I

Fig. 18 is a perspective view 01 a modified slab showing its interiorreinforcement.

Fig. 19 is an end view of a sheet'metal edge member. 4

Fig. 20 is a similar view of a cast or hot rolled metal member. I

Fig. 21 is a similar view of a modified form of cast or hot rolled metalmember.

'Fig. 22 is a sectional elevation of a floor using channeled slabs in aninverted position.

Fig. 23 is a view similar to' that of Fig. 22 showing a modified form offloor with a fireproofing soffit. i

Fig. 24 is an enlarged fragmentary end sectional elevation showing theinsertion of a fireproofing sofllt.

Fig. 25 is a perspective detail of the soifit of Fig. 24. I

Referring now with particularity to the embodiments illustrated in thedrawings, a .preferredform of slab as shownin Fig. 6, consists of aprecast body of set cementitious-material l of gypsum or the like eitherwith or without fillers and admixtures such as wood chips or similarmaterial. The set cemerititious body is provided with edge metallicmembers 2 which are adapted to interlock and inter-engage withcorresponding complementary metal members on the edge portions ofcontiguous slabs as shown in Figs. 5 and 6. For instance,'in the formerfigure one of these members is provided with a tongue and thecorresponding member on adjacent slab provided with a complementarygroove adapted to receive the tongue in a tight frictional joint. As aresult, the two adjacent metal members co-operate with each other toform an effective I beam, thus developing strength and load sustainingcapacity in the structure involving such slabs far in excess of anythingwhich could' be expected by the use of such slabs without these metalmembers.

The metal members 2 are provided with flanges 3 at the top and bottomthereof with inwardly turned end portions 4 embedded in the cemen-'titious body I. These angular ends [prevent the metal members fromaccidentally pulling away from the slab during handling or erection andat the same time add a material stiflenin'g effect thereto. j I

While in Fig. 6 the slabs -I are provided with metal edge members attheir longitudinal edge portions only, yet obviously these parts may beduplicated on all four edges where desirable or necessary. Obviously theflanges 3 may be either flush with or located between the. slab faces.

In the preferred form of slab as shown in Fig. 6, one slab face ischanneled as at 5 completely longitudinally thereof so that the slabitself has a depth or thickness at its edge portions greater than at apoint intermediate thereof. Inasmuch as the load sustaining value oi!the slab is prac tically the load sustaining value of the metal members,it may be and is frequently desirable to utilize such metal members indimensions particularly height which if this thickness or heightcorresponded entirely to the thickness of the slab itself, the latterwould be so heavy as not to be readily handleable. As a result, it isproposed to hollow out or channel one face of the -slab as indicated at5, which thereby reduces therequisite strength as desired. It has beenfound convenient to spring such elements between definite points on themetal members 2 and in Fig. 6 these points are shown to be the top ofthe metal defining the groove at one end and the interior of the hollowtongue at the other end. This definitely locates the series of lateralreinforcements uniformly so that when the body i is cast or poured, theywill occur at uniformlypredetermined points in the body. In order toprevent any displacement of these lateral members 6 during the castingoperation, lighter longitudinal reinforcements I may be provided. As aresult of this construction a definite structural arch is provided sothat even though the minimumthickness of the body I at the top of thearch is of very small dimensions, say one inch and v of such weakmaterial as gypsum or the like, its load sustaining value is excellentdue to this interior reinforcement. When the slabs are placed together,the arch is prevented from becoming deformed or flattened by the slabsat each side thereof, which is a particularly advantageous construction.Y

It will, of course,,be apparent that in instances where there will be noparticular load to be sustained on the-slabs in the direction of itsthicknesss, as for instance in the wall of Fig. 6, these interiorreinforcements may be omitted.-

In Fig. 1 a diagrammatic layout of a two story and attic house isillustrated. which may be constructed almost exclusively of the precastmetal edged slabs above described.

The walls of this house are shown in sectional plan view in Fig. 4.which consists of a series of slabs as above set forth interlockedtogether and extending in a vertical direction. Such slabs as shown forma smooth and substantially unbroken exterior surface to which any typeof finishing material may be applied, such as stucco, clapboards, tile,paint or the like.- The interior of the wall which may constitute thewall of the room may be finished with any desired type of slab or sheetmaterial nailed or'otherwise applied directly to the wall slabs as wellas lath and plaster. In Fig. 5 such a finished material is indicated asa ceiling 8 nailed directly to the slabs i above the same by means ofnails 9 which pene-. trate the flange of the metal members 2. By

driving the nails or fastening devices directly to conceal water, gas orsoil pipes, electrical conduits or the like, or may even be used asheating, cooling or.'conditioning fluid conduits as the case may be.It'will be apparent that inasmuch as these slabs run continuously fromtop to the bottom of the house, the slabs abutting each other at theirend portions, these channels 6 run continuously from top to bottom andhence form effective conduits or enclosing spaces for any particular useas well as effectively insulating the house from heat or cold.

A corner post is shown at III in Fig. 4 to consist of a substantiallyrectangular body of cemen- 7 I titious material having on two adjacentedges thereof a metallic member ll formed to include both a tongue and agroove, the ends of the metal I being embedded in the cementitiousmaterial in the same manner as the corresponding 1 parts of the slab I.This corner post, therefore,

provides interlocking and inter-engaging complementary means to receivethe adjacent slabs in a continuous series.

From the above it will be apparent that mas-- much as the metallicmembers on the edge portions of adjacent slabs form an effective I beam,the walls are particularly stiff without the interposition of columns orstrengthening elements.

The elimination of these parts is particularly desirable where acomparatively cheap yet eih'oient house construction is desired.

The floors of the house of Fig. l are shown in detail in Fig. 6. Thesefloors consist of a horizontal series of these same slabs l arrangedwith their ends abutting the slabs of the walls,

their longitudinal edges engaging each other in an interlocking andmating joint as above described. In order to support the individualslabs and the floor made thereof from the walls, it is preferable toprovide a joint or supporting plate I! as shown in detail in Fig. 7;This plate consists of a substantially T formation ofsheet or cast metalof the requisite strength having grooves l3 and I4 arrangedtherein asshown. In erection, the plate is so arranged -between joints in the wallslabs of Fig. 6 that the groove I3 is enclosed between the adjacent edgemembers on two contiguous wall slabs. Where the frictional contactbetween these three parts is not suflicient to completely sustain anyload which might be put on the floor, the member I! may be nailed orotherwise secured to the edge portions of the wall slabs. When in thisposition the floor slabs are erected to enclose in thasame .manner thegroove H in the supporting plate l2 which may also be nailed to thefloor slabs as shown. By providing such a Jointor. supporting memberbetween each edge of the floor slabs and the adjacent wall slabs, thefloor is effectively and completely supported from the walls and fromthe I beams therein constituted by the mated metal members thereof. Thisconstruction makes a particularly stiff and immobile floor and wallconstruction. The end floor slabs whether longitudinally cut or uncutmay be given additional support intermediate the slab ends by the stepI! in the plate l3 held or secured between wall slabs as shown in Fig.2.

In some instances, the dimensions of the floor, .roof or wall will besuch that more than a number of whole and uncut slabs will-be needed tocompletely form the same. Such a circumstance is shown in the floor ofFig. 5.

There the space between the wall C and the last full slab is less than aslab width. Under these conditions it becomes necessary to cut a slablongitudinally and such a cut slab is shown at I. In order to properlysupport the cut end of the slab, it is proposed to nail or otherwisesecure the metal part I to the wall C, and superimpose thereon the metalmember I", with theneath it so that its hollow tongue is superimposedupon the similar tongues of the parts 2' and)", with the flange 3underlying the out part of the slab I 'In this manner the cut edge ofthe slab is adequately supported against both up or down movements.Obviously nails or the like may be used to secure the parts 2', 2 and 2together or any or all of them to the wall C. Also, the flange 3 may beso located on the part 2 that it will have to be wedged against theunder surface of the cut edge of the slab. This makes for a more rigidsupport.

In like manner, if the wall slabs do not completely fill out the spaceof a wall, they too may be cut longitudinally. In such a case, as inFig. 4 for instance, the part 2 may be omitted as the corner post 10 isalready provided with a tongued member. Parts 2 and 2 are then erectedinplace in the same manner asshown in the right hand end of Fig. 5 tosupport the cut wall slab. I

Where interior walls are to be supported directly upon the floors, 'theconstruction of Fig. 11 may be resorted to, in which the joining plate I2 is used to secure the vertical wall to the horizontal floor.

Where the floor extends over a partition inside of the house, the plateI 2 may also be used as shown in the right hand portion of Fig. 11.

Where partitions exist above and below the floor at substantially thesame point, a Joining plate l5 (Fig. 1) may be used of substantiallycross formation having the same type of grooves as illustrated in Fig.'l. The walls and floors are thus braced in all directions againstdisplacement and supported one by the other.

In the roof construction of Fig. 1 the Joining or supporting plate ofFig. 8-lnay be used.- This consists of a T formation I 6 where the headof the T is slightly at an angle to the main body. In position thiselement is shown in Fig. I, the body of the T being clipped in the samemanner as the device of Fig. 7 between the adjacent metal edge membersof the wall slabs and the top of the T is joined to the roof slabsarranged at an angle to the wall.

It is contemplated that the roof slabs will be laid on the roof supportswith their length running .in the direction of the slope of the roof,

that is, from eaves to peak. Due to the fact that these slabs are madein substantial lengths, that is, from 6 to 15 feet, dependent upon thethickness and desired load sustaining value thereof. they may be laid atrandom lengths whether for walls, floors, partitions or roofs, it beingonly necessary to abut ,the ends of such slabs and continue until theentire area has been covered. It is preferable, of course, torbreakjoints in order that no particular weakness may be developed at any onelocation.

In order to tie the roof slabs together on each side of the roof peak,the construction of Fig. 15 may be utilized where the particular roofslab which occurs at or near the peak is too long to end directly at thepeak. In such cases the slab body and the metal members 2 may bepartially sawed through by any suitable device-and in no case throughthe metal constituting the flange s, leaving this portion intact andunsevwalls solidly without regard as to where these openings will occur.After the wall has been in place, the window or door openings may thenbe marked out and such opening cut therefrom by hand or power. Inasmuchas the set cementitious material of which the slabs are made may bereadily cut and the gauge of the metal on the slab edges may becomparatively light, this severing or cutting out of the openings may beaccomplished without difficulty. Such openings may occur as shown at I!in Fig. 1, where the width of the opening is substantially the width oftwo slabs or such opening may occur as at l8 where this width terminatesother than at Joints between the slabs.

In order to prevent any tendency of the short slab pieces i 9 fromdropping, where the frictional contact between the slabs is notsuillcient to prevent this, the exposed metal Joints may be securedtogether as shown in Fig. 6. There spots 20 of solder or the like may beused or the entire joint may be filled for a substantial extent withsolder as at 2|. Onthe other hand, this joint may be accomplished bywelding either in spots or along a substantial extent sufllcient tosecurely tie the short pieces 9 to their neighbors and prevent anydropping or accidental displacement.

Another form of joining the short pieces 'to their longer neighbors isillustrated in Fig. 9. This consists in the provision of a supportngplate 2| shown in detail in Fig. 10, having an extended body withangular ends 22 each of which is provided with a groove 23 adapted to beclipped and enclosed between the metal members on adjacent slabs. Wheredesired, these ends may be additionally nailed to the slab edges wherefrictional contact is not sumcient to prevent undue movement.Intermediate the ends ofthis tie or bridging piece 2|, is an angularshelf or step 24 adapted to underlie the short piece of slab iii. Inthis manner the cut slabs dow or door bucks or frames may be naileddirectly to the exposed edges of the slabs as de-' sired with theminimum amount of effort and labor.

.Due to the remarkable load sustaining value which slabs of thisinvention have, by reason of the mating and mated metal elements at eachedge thereof, spans on supporting elements may be even greater than thetotal length of the slabs constituting a floor or roof. Suchconstruction is shown in Fig. 14.

In this construction which is drawn substantially to scale, for purposeof illustration only, I

beams or channels are shown at 25 erected on say 16 ft. centers. Thesebeams 25, of course,

" sary intermediate beams.

aoeaosv may be either floor or roof beams as the case may be. In thisconstruction slabs substantially ft. long are utilized which, of course,is less than the beam spacing. These slabs may be from v 10 to 16 incheswide and of a depth or thickness particularly at their edge portions,and the ma terial of metal members thereon of a gauge, sufficient tosustain the load which the floor is designed to take.

In erecting such a floor or roof, a temporary shore 26 is erectedbetween beams 25 and the floor or roof slabs then laid at random,preferably breaking joints thereon as shown.

For instance, the slabs A and B are laid in place, their adjacent endsbeing supported by the temporary shore 26. Other slabs C and D are thenlaid at random, dependent upon the area of the floor or' roof to beerected but inasmuch as we are only particularly concerned here 20 withthose slabs directly supported by the beams 25, further mention of slabsoutside of this zone will not be made.

' Slab E is then put in place, one end of which is supported by the lefthand beam 25, so that the longitudinal and/or end edge metal elementthereof engages the corresponding and complementary metal member of theslabs A and C..

Due to the fact that a considerable length of the slab E is meshed witha corresponding metal element on the left hand side of the beam 25, theright hand projecting end thereof cantilevers over the beam withstiffness and resistance. The slab F is then erected, meshing in exactlythe same manner as specified for slab E and is then followed by slab G.The temporary shore 26 effectively supports the slab F until the otherand subsequently erected slabs are in place to relieve .the shore of itsload. The slab G cantilevering over the left end of the right hand beam25 effectively supports the end of the slab .F. In these circumstancesit is, of course, understood that all of the slabs are preferablyprovided with metal members on all fouredges rather than on merely thelongitudinal edges.

: In the same manner, the slabs H, I, J, K, L, --M, N, O, P etc. areerected. After'e'rection as above set forth, the temporary shore may bere moved, in which event the slabs F, M and those similarly located haveno direct support from the beams 25 but on the contrary are entirelysupported by the surrounding slabs, which in turn derive their supportfrom the beams. Due to the factghowever, that these indirectly supportedslabs are entirely surrounded by other slabs directly supported by thebeams, and that both sets of slabs are interlocked and intermeshed onall four edges, there is a continuity of I beam construction in thedirection of length of the slabs from beam to beam which has been foundtaining value. It will be obvious, of course, that such a constructionis particularly-advantageous if wide beam spacings may be used with theelimination of many of the heretofore thought neces- It will also beapparent that instead of using the beams 25, they may be replaced by thewall construction. of Fig. 6 where the individual slabs are supporteddirectly from the wallslabs themselves.

There will be some instances, of course, where buildings or houses willbe designed, and particularly heavy furniture or machinery located atdefinite points, and the floor or root at these -75 points requirespecial reinforcement. Such reinto have tremendous and remarkable loadsus-' forcement is shown in Figs. -12 and 113. There Fig. 13 shows aparticularly heavy reinforcement construction 21 conformingsubstantially to the, tongued member 2 in the slab A. In this case themember 21 is likewise provided with top and bottom flanges 28 overlyingthe faces of the slab A. In Fig. 12 a complementary reinforce 29conforming-substantially to the groove in the member 2 of slab B is usedto inter-engage and mesh with the reinforcement 21 in the adjacent slab.This reinforce 29 islikewiseprovided with top and bottom flanges 30corresponding to its complementary part 21. These meshed reinforcementswhich are in fact I beams, may extend from wall to wall of the floor orroof construetion or may extend'from beam to beam as the case may be, ormay simply extend over several end joints of slabs making up the flooror roof to add additional stifiness and strength thereto. In someinstances it will not be found necessary to provide these reinforcements21 and 29 with flanges 28 and 30 as shown, but on the contrary the gaugeor dimensions of such parts will be sufilcient'to give the requisitestrength without such flanges. This is particularlytrue because of thetongue and groove which occurs in the web as these parts lend stiffnessand prevent undue twisting under strain. I

- Where it is not desired to secure a ceiling slab or the like directlyabutting the undersurface of the. floor slabs, the construction shown inFigs. 2 and 3 may beused. There ceilin'g slabs 3| are shown, each havinga-metal member carried by the longitudinal edges thereof, one member. 32

having a groove and the other member ,33 a corresponding tonguereceivable in the groove; As shown, the ends of each of these edge metalmembers are turned back into the slab as at 34 to prevent the parts fromaccidentally becoming loosened from the slabs to which they areattached. The metal member 232 is provided with an upstanding flange35-perforated at intervals as at 36 and adapted to receive hooks or thelike 31 which are in turn carried by a plate 38 conforming closely to abeam enclosed between the interlocking members 2 on the slabs above.Where desired, this member. 38 may be additionally nailed to the slabedges as at 39.

It is to be noted that the upwardly projecting I flange 35 of theceiling slab edge member is in Fig. 5. As a matter of fact, the sameceiling' slabs, for uniformity of erection and making unnecessary theprovision of the more than desired few types of slabs, may be likewiseutilized as the interior wall coverings to enclose the face channels ofthe wall slabs as above described in connection with Fig. 4.

In some instances it has been found that in the course'of manufactureand handling, dirt, plaster or the like adheres to the metal facing ofthe slab edges, with the result that it is difficult to get a completelytight joint between the metal members on adjacent slabs.

be desirable to set back a portion of the web of the metal members onthe slabs as shown at 40 in Fig. 4. In such case the part (will make itssurface contact with the corresponding part 42 without regard to whetheror not the part 40 In order to at least eliminate part of thisirregularity, it may located below the'plane of the surface of suchcontacts with its corresponding face on the adjacent metal member andthus at least half of these irregularities, are eliminated.

Where slabs are desired with exceptional lateral stiiiness withoutreliance entirely upon embedded reinforcing rods or the like, themodified construction shown in Figs. 16 and 17 may be used. Therenotonly are the longitudinal edges of the slabs-made thicker than theintermediate portion as in Fig. 6, but intermediate lateral ribs 42 areprovided. The body material between the lateral ribs and thelongitudinal edges may be arched as shown in Fig. 17 to develop all ofthe strength inherently present in the material of which the body ismade. While in. Fig. 17 the reinforcing rods as shown in detail in Fig.6 are used. yet it is to be noted that the lateral ribs 42 'are notprovided with such reinforcements. This is particularly desirable in aconstruction in which the channeled face is to be used to carry pipes,conduits, or heating, cooling or conditioning fluids. If but the onestandardized form of slab shown in Figs. 16 and 17 is to be used, due

' to the fact that these ribs 42 do not carry reinforcing rods, they maybe readily and quickly knocked out with a hammer or the like where notneeded to accommodate such pipes or conduits. The underside of suchslabs may carry decorative molding 43 cast thereinto which gives apleasing eifect to a ceiling where no covering slabs are to be used.

In some instances it has been found desirable to use a slab having asubstantially plane face at each side thereof rather than the slab ofFig. 2,

for instance. This is particularly desirable where the floor slablikewise is relied upon to form an under-flush ceiling. In suchinstances the modified form of slap in Fig. 18 may be used. It will benoted from an inspection of this figure that the reinforcements 6 and Ihave been duplicated at the top and bottom and a hollow interior orcavity 44 formed in the slab during its process of manufacture. In thisway any desired depth of slab may be useddependent upon the loadsustaining requirement of the'location in which it is to be used, whilestill maintaining the total weight of the slab at a desired optimum. r

In most cases it has been found desirable to form the metal member to beattached to the edge of the slab of sheet metal as remarkable loadsustaining values may be secured therewith even in comparatively lightgauge material. This is due as above set forth to the intermeshing ofcomplementary parts which form effective I beams. Where, however, metalmembers are desired which are particularly resistant to sheer, amultiplicity of tongues and grooves may be provided as' shown in Fig. 19which illustrates ones uch member 2 having a plurality of tongues 45.Any number of these tongues may, of course, be duplicated to provide therequisite sheer resistance.

In slabs having excessive lengths, where it is notdesirable to providean additional reinforcement such as shown in Figs. 12 and 13, thismetaL;

member may be cast or hot rolled rather than of sheet metal and such aconstruction is shown in Fig. 20. It conforms closely to the conflgura-ytion of the metal member 2 in Fig. 18 for instance, except that it is acast or hot rolled section. In such a case it is to be noted that theweb is in one continuous piece and hence has all of the strengthattributable to the present hot rolled structural sections now commonlyin use whether of the channel or I beam type. When twp of these partsare placed together as in contiguous slabs, not only is its effectivestrength increased but it is more than doubled due to the fact that thetongue 41 and the corresponding groove interlock and definitely matetogether, thus possessing a resistance to sheer not present in sectionsnot mated.

In Fig. 21 a construction similar to Fig. 20 is shown except that aplurality of tongues 41 and grooves 48 are provided.

In some floor deck constructions it will be founddesirable to invert theslabs I and make use of the channel 5 therein to contain an insulatingor load sustaining dry or wet fill such as dry cinders, cinder concreteor even concrete itself. Such a construction is shown in Figs. 22 and23. In the former, the slabs are mated together as above describedthough arranged inan upside down manner with the channel facing upward.This channelled face may then contain a fill 49 of any desired materialor it may be left empty. In any case, a floor 50 may belaid directlyupon the tops of the contiguous slabs, which will assist in loaddistribution.

Where the fill to be contained by the channel is of a wet nature whichmight cause seepage and consequent rusting of the metal members orweakening of the body of the slab, the entire inner surface thereof maybe coated with a suitable waterproof material as shown at 5| and a weephole 52 provided at the bottom of the channel. As a consequence anyexcess water will be permitted to completely drain therefrom withoutseepage into the slab body. This will be found to be of extremeadvantage during the construction of a building where the open slabs areput in. place and then before other work can be done thereon, waterwould otherwise accumulate in the slab such for instance as in the caseof a rain storm. In the construction as shown, this water wouldimmediately run out of the slab without producing any detrimental effecton the slab itself.

Where the slabs are arranged as shown in these figures, it may be founddesirable to slightly re-arrange the lateral strengtheningreinforcements 6 so that one end thereof enters the metal forming thetongue on one edge of the slab and rests upon the metal forming thegroove in the corresponding member on the opposite edge of the slab.

Such a construction utilizes a full load sustaining value of the metalmembers 2 while utilizing the slabs themselves as a form or containerfor the fill. This assembly also has the advantage of producing asubstantially flat under ceiling.

While in Fig. 22 no suspending beams or purlins are shown other than themetal edge members themselves, yet obviously such a combined floor andceiling may rest upon suitable beams where this is desirable.

In Fig. 23 a slightly modified form of floor is shown, in which aconcrete or other plastic floor 53 has been poured directly upon theill] 48.

In this case the slab body I is provided with a cutaway portionimmediately, beneath the flanges rof the metal elements 2 and this spaceis filled with the soilit slab 01' P18. 25 as shown more in enlargeddetail in Fig. 24.

This sofiit consists of the slab 54 having embedded therein a hangerelement with an upstanding portion 55, the lower part of which in splitand bent in opposite directionsand embedded in the body of the sofllt.Obviously this upstanding part II may be continuous as shown in Fig. 25,or it may be interrupted intermediate its length. It also has acorresponding tongue or groove to coincide with the mated edge mem-'hers I as shown in Fig. 24. In any event, nails may be used wheredesired to assist in securing the sofiits tothe slabs. In erection aslab I will be put inplace, then the soflit erected, which will then befollowed by the next adjacent main proper dimension, may afford adequatefire protection to the bottom flanges l of the metal elements 2 while atthe same time maintaining. a desirable flush ceiling beneath the entirefloor orroof deck. v

From the above it will be obvious, of course,

that there has been here presented a system of building constructionwhich maybe made completely from a comparatively few types of slabswithout the-use ofbeams, columns, or the like, but which on thecontrary, due to the metal mating' members on the edge portions formeffective beam construction-in andof themselves. Such a construction ofslab insures rigidity, stability and extreme load sustaining valuewhether placed on end, on the .side or can face. Such a construction isof particular advantage where com paratively small dwellings arecontemplated.

Where larger houses or constructions are to? be made therefrom, thevarious sections or parts may be made correspondingly heavy orreinforced, all as above set forth. f

As a result, a completely flexible system results which may be readilymanufactured in comparatively few sizes and shapes and 'yet which willaccommodate most building conditions.

While the invention has been shown and described with .particularreference to specific em-.

bodiments, yet obviously it is not to be limited thereto but is to beconstrued broadly and restricted only by the scope of the claims.

I claim: 1. A precast slab of set cementitious material havingcomplementary metal members on oppotop of the hollow groove 'of themetal members respectively.

I 3. A precast slab of set cementitious material having metal members onat least two opposite edgesthereof, one face of the slab beingsubstantiallya plane surface, the other face of said such a constructionwhere the. sofllts are of slab including substantially an arch, andreinforce members extending between the metal edge members andembedded'inthe body and conforming substantially tothe arched face ofthe slab.

. 4. A precast slab of set cementitious material having metallic edgemembers on at least two opposite edges, one of the slab faces being'sub-,

stantially aplane surface, the other face being arched longitudinally ina plurality of arches, and a lateral stiflening rib of set cementitiousmaterial located between two of said surfaces.

5. A building construction includin'g'two contiguous slabs, each slab ofset cementitious material having metallic edge members, the adjacentedge members on two slabs being interlocked together in a mating Joint,and an area of solidi-3 fled fused metal securing the mated metalelements together.- v

r 6. A building construction comprising a series of precast slabs ,ofset-cementitious material end to end and laterall'y'adiacent otherslabs, each slab having metal elements on at least tweenposite edges,the adjacent metal elements on contiguous slabs being mated together,the series of slabs arranged end to end having channels on one facethereof extending the complete. length of each'slab so that saidchannels extendcontinuously from slab to slab, and facing sheets orslabs; covering said channels and secured to said slab's.

7. A precast 'islab having-a body-of set oenientitious materials-havingmetallic members-.-

on at least two opposite edges thereof, one of said members having agroove/ and the other a tothe mating tongue, one of said mbershaving-an. edge portion substantially all? slab face and embedded in theslab body and lying between the plane of the top and bottom ght an: es

faces of the slab, the material of the slab body being of greaterthickness at its edge-portions thanv its thickness intermedia thereof.

8. A precast slab havi g a body of set cementitious material havingmetallic members on at least two opposite edges, one of said membershaving a tongue and the other-.9, complementary groove, each of saidmembers having a flange on each side of the tongue or groove, extendingsubstantially parallel to a slab'face, one of said flanges of eachmetal' member being flush with a slab face and the other embeddedbetween the slab faces.

9. A precast slab having a body of set cem'entitlous material, two edgesof which are,

substantially covered with metal, one metal covered edge being providedwith a tongue and the other withfa complementary groove, the metal,

covering-of each of two edges having a flange completely embedded in theslab body and a portion' substantially parallel to said flange lyingCLARKE r. navrs.

subflantially flush with a slab surface.

